Improvement in preserving iron from corrosion



V, UNITED STATES PATENT FFIQE,

OF NEW YORK CITY, NI Y. f

IMPROVEMENT IN'PRESEIRVING tReN .FBi-Q'IYLC RRQSIO Q- Specificationforming part of Letters ?atentll 1o 43,630, dated July 19, 186

To all whom it may concern:

Be it known that I, CHAR-LES DE BUSSY, of

Paris, in the Empire of. France, have invented process for preservingiron from corrosion as.

produced by the influence of air and sea-water to be as follows: j

The means hitherto employed for preservin g iron from any corrosiveactions are based either on'galvanic processes, or on the use ofcoatings intended to resist said corrosive actions.'-.When substancesare thus applied in a mechanical way to preserve the surface of ironthey offer a very slight adhesion. Moreover, in many cases, according tothe nature of the metallic oxide used for the coating, they will exert adirect corrosive action, such as takes place withminium when applied tothe bulls of iron-built vessels. Acting upon these data, I have come tothe conclusion thatin'order to obtain a most satisfactory result inpreserving iron a coating must be used. whose adhesion shall be theresult of a chemical action on the metalitself. Among the variousmatters that will fulfill this condition, I prefer using the'fusible andinsoluble ferruginous compounds, they both protecting the surface of theiron and filling up, by reason of their fusibility, those imperceptiblefissures and cavities which always 'occur in wro.ught-iron, owing to theporous nature of the metal, and-to the imperfections unavoidabl yarising from the forging or rolling process.

' A great number of compounds may be used, each answering the purpose ofthis invention, as above set forth. its nature, and how it is or may becarried into efl'ect,'l will now describe the manner in which I employone particular compound by which 1 have obtained the best result. Theprocess which I consider the mostsim ple and reliable consists insubjecting the iron pieces to be preserved to the action of phosphorusat a high temperature, so as toproduce on their surface a thin layer orcoating of melted p'hosphidc of iron. 'This coating proves to be very adhesive, and is hardly acted upon by the corrosive agents to which ironis commonly exposed. This operation may be efl'ected by exposing thered-hot iron direct to In order to show clearly and economical way is byheating the pieces in cases or chambers similar to those. ofconverting-furnaces, the 'pieces being embedded therein in a brasque ormixture composed of charcoal or coke dust impregnated with a solution ofacid phosphate of lime. Pieces of large'si'ze may also be brought to aweldingheat and then be laid on a bed or b'rasque courposed as aforesaidand well dried and covered up with the same materials. The heat radi:ated by the piece is sufliciently powerful'to cause the distillation ofthe phosphorus and its combination with the iron..

This process may be advantageously applied in many instances, such asfor iron plates to be used in ship andhouse building, anchors,gun-carriages, water-tanks, &c. Itis pecti liarly adapted for ironplating oriron shields or armors, for preventing the rapid deteriorationof which no eflicient means have been devised hitherto.

I wish it to be distinctly understood thatQI do not confine my processto the use of phosphorus only, as I may use in its stead-any other bodyacting in the same way, such as arsenic, antimony, &c. ,The mode ofapplying these various substances will necessarily have to be somewhatmodified, according to their reactions and the nature of the compoundsfrom which they are derived; Arsenic, for instance, will be applied iiithe same way as phosphorus, with the only difl'erence that the brasqueshall be composed of a mixture'ot charcoal and arsenious acid with lime,carbonate of lime, or-an alkaline carbonate.

Having thus described myinvention and the several modes in which Icontemplate its ap-" plication, I claim as my invention and desire tosecure by. Letters. Patent ot' the United States- 1 The protecting ofiron plates, beams, and

